Parboiled rice is preferred over white rice by many consumers for its texture, appearance, flavor, aroma, and recipe tolerance. However, due to the pretreatment of the rice in the paddy form which produces parboiled rice, the grain is rendered longer-cooking than milled white rice. Most parboiled rice of commerce calls for immersion-cooking of at least 20 minutes in boiling water to prepare the parboiled rice to the desired edibility. During the process of converting rough rice to parboiled rice, the paddy is soaked, steamed, dried, and then milled. It appears that the heat treatment involved in this processing reduces product rehydratability and renders it harder and longer to cook.
Many attempts have been made to produce an instantized parboiled rice having the texture, appearance and flavor characteristics of eating quality parboiled rice but success has not been completely achieved. In U.S. Pat. No. 2,720,460 entitled "Production of Quick-Cooking Rice" techniques are described for producing instantized rice by hydrating rice grains in stages but did not consider parboiled rice as the starting material. U.S. Pat. No. 2,438,939 entitled "Quick Cooking Rice And Process For Making Same" describes a milled rice (not parboiled) cooked in boiling water until its starch is substantially gelatinized and its moisture content is raised to about 65-70%, cooled and quick dried by removing moisture from its surface at a rate sufficiently faster than it can diffuse thereto from their interiors at 140.degree. C. for 10 to 15 minutes. Another U.S. Pat. No. 3,408,202 entitled "Process For Preparing A Quick-Cooking Rice" prepares a quick cook rice by soaking parboiled rice in water below its gelatinized temperature 160.degree. F. to increase its moisture content to 15-50%, steaming the rice to temperatures of 180-212.degree. F., reimmersing the rice in water below 160.degree. F., steamed again and reimmersed again and then dehydrating the cooked rice. This multiple step process is time consuming and complicated. U.S. Pat. No. 2,903,360 entitled "Method Of Making Quick-Cooking Cereals From Parboiled Grains" soaks parboiled rice in water for 2 to 5 hours at temperatures between about 50.degree. F. and 82.degree. F. to a moisture content between 45 and 55% compared to temperatures between about 130.degree. F. to 160.degree. F. to a moisture content between 65% and 77%. The rice is then boiled in water for about 2 to 5 minutes, separating the boiled grains from the boiling water, spraying the grains with cold water to about 130.degree. F., squeezing the cooled grains to 1/3 to 1/5 their thickness, washing and drying the grains. This multiple step process is also time consuming and complicated. Finally, U.S. Pat. No. 4,361,593 entitled "Process For Preparing Dry Quick-Cooking Parboiled Rice And Product Thereof" prepares dry parboiled rice by soaking rough rice in water to increase the moisture content to 30 to 45% by weight without effecting substantial gelatinization, steaming the hydrated rice under conditions effective to partially gelatinize the starch granules, tempering the partially-gelatinized rice at temperaturs below the gelatinization temperature of the starch while maintaining the level of moisture above 20%, drying the rice to a moisture content less than 15% and milling the rice. This process occurs within the hull of the rice. Other references are known to produce quick-cooking rice but no references are known which describe the process of this invention relating to the production of an instantized parboiled rice which is unique in its operation to provide an outstanding quality product having the texture, appearance and flavor characteristics of eating quality parboiled rice finished product.